Compression spray gun



jan. 21, 1930. w P, BUCHANAN 1,744-,208

COMPHESSION SPRAY GUN Filed April 12, 1929 2 sheexs-sneet 1 I. W Rffuchananq/ INVENTOR ATTORNEY Jam 21, 1930- l. w. P. BucHANAN 1744203 COMPRESS ION SPRAY GUN Filed April 12, 1929 2 Sheets-Sheet 2 [EZEfiz/Lchanan) INVENTOR 2 7 ATTORNEY Patented Jan. 21, 1930 PATENT OFFICE' ISAAC W. P. BUCI-IANAN, OF LEBANON, TENNESS EE colurnrzssrorrv SPRAY GUN Application filed April 12, 1929. Serial No. 354,688.

This invention relates to a compression spray device or gun, the present invention on February 15, 1928, Serial No. 254,510, the

lgeneral object of the invention being to provide means whereby the liquid is ejected by pressure as well as suction so that the device will operate with the minimum amount of 10 compressed air, this air being used to create pressure in the container above the liquid therein and also used to create suction in the liquid tube and to act on the air escaping from the tube to create a spray. This compression structure, although applying swaths decidedly wider than the suction structures now on the market, requires approximately one-third of the compressed air usediby them. This fact allows an outfit of compressor plant and 0 gun, weighing approximatelyi fifty pounds, as againstfrom four to ten times this Weight of plants now being marketed, and which last are only capable of inferior functioning. Also in addition to this first-time-accomplished portability, only a 1/2 H.` P. motor is required, which can he attached, without danger, to any electric light lamp socket.

A further object of the invention is to provide a tip having a slot therein for producing a fan-shaped spray and to so form the tip and its slot that the central portion of the fanshaped spray will be thicker than the end portions or edges of the spray, so that the swaths of paint or the like,`sprayed on a 5 surface by the device, can be made to overlap Without the laps being thicker than the other portions and without causing runs.

As will be seen, the interior walls of the tip terminate in the slit, and so converge as to produce a fan shaped spray of fixed flare limits. v

The object of my slitted tip is to produce afan shaped spray and which so co-acts With the adjustable liquid control valve as to produce fan shaped sprays'varying in width between one-half inch and sixteen inches, or more. j

A further object of the invention is to progo vide an adjustable mixing chamber, 'With stabilizing means for producing a homogene'- j the atomization action.

RassuED ous cross section of a fan-shaped spray, this v mixing Chamber permitting the air and liquid to intermingle under pressure before escaping from the tip, thus producing a fan-shaped spray of uniform cross section and allowing the fan shaped spray to be arranged either vertically or horizontally.

A further object of the invention is to provide adj ustable means for controlling the flow of air into the eduction tube for regulating w This Valve is located so as to operate on the air after it has contacted the liquid, and thereby increases or decreases the pressure on the liquid.

Another object of the invention is to provide a disk carrying a valve, the disk being located between the container and the atomization head and acts to prevent the liquid in the container from entering the head, While o permitting air to enter the cont-ainer from the head to place the contents thereof under pressure. t

Another object of the invention is to provide a pressure control valve for closing the air supply line to the container so that the container can be removed andfilled without stopping the power plant` that Supplies comrpressed air to the device.

A still further object of the invention is to provide adjusting screws in the eduction tube fo centering the liquid tube in the eduction tu e.

Another object of the invention is to provide a manually operated valve interrupting the flow of lic uid through the liquid tube ,85 without interfering with the air flow, so that the spraying can be stopped instantly and then when the valve is opened to permit the liquid to flow again, the same texture of atomization is produced as was produced before j the valve Wasclosed, with simple means for j adj usting said valve so as to control the fineness and volume of spray. j The adjustable liquid valve for starting and stopping the flow of liquid, also gauges the amount of liquid delivered at each trigger operation.

This adj ustment allows this Valve to co-act with the slitted tip so as to produce fan shaped sprays varying in width from onehalf incll to sixteen inches or more.

Large quantities of liquid entirely fill out the fixed air contour of tlle fan shaped spray, and smaller quantities of liquid fill the center, only, of this fixed air contour.

This invention also consists in certain other features of construction and in the combination and arrangement of the several parts, to be hel'einafter fully described, illustrated in the accompanying drawings and 'specifically poillted out in the appended claims.

In describing the illventioll in detail, reference Will be had to the accompanying drawings wherein like characters denote like or corresponding parts througllout the several views, and in which -2- Figure 1 is an elevation ,of the invention.

Figure 2 is a top plan view.

Figure 3 is a Vertical sectional view, with parts in elevation.

Figure 11 is a section on line 4-4 of Figure 2.

Figure 5 is a section on line 5 5 of Figure 2.

Figures 6 and 7 are views of the valve carrying disk.

Figure 8 is a longitudinal sectional view through said disk.

Figures 9, 10, 11, 12 and 13 are views of the tip. w

In these dl'awings, the numeral 1 indicates a colltainer, the neck of whicll is threaded to receive a cap 2, the cap being provided with a hollow dome 3 into which air is introduced from a suitable source of supply through a tube connected with the inlet member L1, which in turn is connected with a valve casing 5, one end of which is threaded in a hole ill the dome. This member carries the needle valve 6, the closing of which prevellts air from entering the dolne. The valve casing 5 also carries a safety valve 7 for prevellting damage to the parts by excessive pressure.

A dependillg tubulal' part 8 is formed at the center of the dome alld a section 9 of a liquid tube is thl'eaded into the depending pol'tion, the lower end of the section extellding to a point adjaccnt the lower end of the colltainer. The other section 10 of the liquid tube is threaded into a hol'izonlal opening formed ill the upper end of the depellding part so that liquidI can pass from the section 9 through the tubulal' part 8 into tlle section 10v` it being` seen that the section 10 extends horizontally anfl at right angles io the section 9. An eduction tube ll surrounds the section 10 of the liquid tube and has one end threaded into an opening 12 forllled in olle side of the dolne and all air tube 13 conneets the inner end of the opening 12 with the lower part of the chamber ll formed by the hollow dolne so that air can pass from the Chamber 14 through the tube 12% into the eduction tube.v As will be seen, .the section 10 of the liquid tube passes through the opening 12 and is not in communication therewth.

The air tube 18 is provided with an opening 15 which is eontrolled b a set serew valve 16 threaded through a paciiing gland 16l in the dolne, so that by adj listing the set screw valve, the escape of air into the eduction tube can be regulated. This arrangement permits the air passing to the eduction tube to be regulated from the exterior of the dome and While the device is in operation.

It will, of course, be understood that after the valve 16 is adj listed, the same amount of air will always be passing to the eduction tube, since thev colnpressor is delivering the same amount of compressed air to the dome, and all of this air will pass through the tube 13 to the eduction tube. By adjusting the valve 16, the passage of the air to the eduction tube is more or less restricted, and therefore causes more or less pressure on the liquid in the container.

The fiow of liquid into the section 10 of the liquid tube is Controlled by a needle valve 17 passing through a packing gland 18 in the head, with its pointed end engaging a seat 20 against wllieh the inner end of the section 10 abuts. Tlle outer end of the needle valve is threaded in the head 21 of a tubular stem 22 which is slidably arranged in the upper part of the handle 23 of the device, this handle having a horizontal part 24 at its upper end which is bolted or otherwise secured to the top of the dome. A knurled member 19 is fastened to the stem of the needle valve to facilitate turlling of the same. A coil spring 25 is arranged on the stem 22 and bears against a part of the handle and head 21 and acts to hold the needle valve on its seat 20. A trigger 26 has its upper forked end pivoted to the part 24: of the handle, a portion of the trigger engaging the head 21 so that When the tl'igger is moved rearwardly b one or more of the fingers of the hand grasplng the handle the needle valve will be moved to open posltlon.

A tip 27 is threaded on the outer end of the eduction tube so that it can be adjusted toward alld away from the end of the section 10 of the liquid tube which protrudes from the eduction tube. This tip is formed with a slot 'S and with a collical illterior part 29 and at 'the point where the slot enters the Chamber :formed by the conical part, a substantially elliptieal opening is formed for the escape of the nlixture of air and liquid so that a fansha ped spray is p l'oduced, the center of which is' of greater th irkness than the ends or edges. The Chamber formed by the conical part 29 provides a nlixing chalnber wherein the liquid passing from the section 10 of the liquid tube and the air passing from the eduction tube call interlnillgle before the mixture escapes from the split in the tip. The tip is locked in adj usted position by the nut i `the container into which is. threaded on the eduction tube and the gasket 31 which is placed between the nut and the rear end of the tip.` By making the tip or nozzle adjustable, the slot therein can (be placed in either a horizontal or Vertical position, so that` the spray will pass from the nozzle in either a horizo'ntal or Vertical position.

While the drawings show the section 10 of the liquid tube passing entirely through the eduction tube, I qfind that this section 10 can be greatly shortened or even omitted without interfering with the operation of the device.

A disk 32 is placed between the neck of the container and the c p, gaskets 33 being placed between the disk and the cap and between the disk and the neck of the container to make a liquid and airtight junction at this point, said disk being formed with an opening 34 therein which is closed by a flap Valve 35 opening downwardly so that air can enter the container froni the dome, but liquid cannot pass from the dome. A handle 36 is connected with the disk to facilitate its re,-

moval. The section 9 of the liquid tube passes snugly through a hole 37 formed in the center of the disk. A threaded projection 38 is formed on the top of the part 24 of the handle and is designed to receive an extra tip 39 which may be substituted for the tip 27 ,the tips being of different sizes. Of course, more than one projection 38 can be receive other. tips.

From the foregoingit will be seen that when the inlet member 14 is connected bya hose to a source of compressed air and the Valve 6 opened, .the air will enter the chamber 14 formed by the hollow dome and some of this air will pass through the Valve covered opening in the disk 32 into the container and thus place the contents of the container under pressure. This will tend to force the liquid in the container through the section 9 of the liquid tube, but the liquid is prevented from passing into the section 10 by the needle Valve 17. Someof the air in the chamber 14 will pass through the tube 13 into the eduction tube so Qthat when the trig'ger 26 is operated to open the valve 17, the liquid will flow through the sections of the liquid tube into "the mixing chamber in the nozzle or tip,

from the' eduction tube,

where it will be mixed with the air passing this air passing from the eduction tube also creating a suction in the liquid tube so that the liquid is ejected both by pressure and by suction. The mixture of air and liqhid passing through the' slot 28 will take the form of a fan-shaped spray and due tothe elliptic'al shape of the opening, the spray will'be of greater thickness at the i center than at its ends or edges, so that the swath of paint or other material being sprayed on a'surface'can be overlapped without unduly thickening the overlapping porttexture or quantity of 'fan-shaped spray. If placed on the part 24 to producing runs at said lbe adjusted until the swath is uniform.

This tip, with the adjustable mixing chamber formed by the tip and the outer end of the eduction tube, will produce fan-shaped sprays up to twenty inches in width at the ordinary distance of application, and attention is called to the fact that while the adjustable mixing chamber is apparently like the atomizing feature of my hand spray, patented May 15, 1928, No. 1,670,235, itis not only en irely different in its function, but. it is for an entirely different purpose. In said hand sprayer, since the hole in the tip is very small, the air cannot escape as rapidly as it is supplied and the consequence is that here 1s a greater or smaller pressure exerted on the liquid emerging from the liquid tube, and this liquid is therefore allowed to mix with smaller or larger quantities of' air, thus producing Variable atomizations. The mixing chamber in this application, however, does not allow air to back up and control the emerging liquid, as the long slit in the justable tip does not appreciably change the spray and the .only obj ective served by this'arrangement of parts is the controlling of` the uniformity of the the tip i's too close to the liquid tube, leads'of unatomized liquid occur at the Corners and elsewhere and the tip must be moved away from the end of produce a homogeneity of tip permits the air to escape. Thu-s this ad-" passes from the central part of the slit and I nothing but air passes from the ends of the slit, as the air envelopes the reduced quantity of liquid and thus this reduced quantity of liquid forms a fan shaped spray of smaller width.

Thus the peculiar form of nozzle, co-acting with the adjustable liquid Valve, enables the Vdevice to produce fan shaped sprays of Varying widths. I a

The valve disk 32 permits air to enter the container and prevents liquid from reaching the.head and it Will prevent the gun from spraying through the air tube 13 when the gun is tilted more than u'sual. The pressure control Valve 6 can be closed without stopping the power plant so that thev container'can be refilled or changed.

The section 1.0 of the liquid tube is centered in the eduction tube by three small screws 40 and by adjusting the needle Valve f D17 .in the head 21, the amount of liquid passing through the liquid tube can be Controlled or regulated when the Valve is open.

This device, while adapted to agricultural and horticultural needs, is mainly intended for the spray application of paints and lacquers and can be used with a minimum amount of compressed air and as it is of small weight, it can be easily carried from place to place. As but a small power plant is necessary to furnish the air, the motor of the plant can be used with the ordinary house-current. The texture of atomization is from the faintest tint to any desired degree of coarseness;

Therefore, we have a portable and an electric lamp socket attachable plant doing much faster work than competing plants that are neither portable nor capable of being attached, for their power, to ordinary electric light sockets.

The slit in the tip may be formed by a straight slot, as shown in Figures 9, 10 and 11, though it is preferable to form it by a V-shaped slot, as shown in Figures 12 and 13.

It is thought from the foregoing description that the advantages and novel features of the invention will be readily apparent.

It is to be understood that changes may be made in the construction and in the combination and arrangement of the several parts, provided that such changes fall within the scope of the appended claims.

lVhat I claim is 1. A compression spray gun for use with 1 a supply of air under pressure, compri'sing a liquid container, means for introducing com- -pressed air into the container to place the liquid therein under pressure, an eduction tube associated with the container and through which some of the compressed air passes, adjustable means for controlling the escape of air into the eduction tube after it contacts the liquid, a liquid tube connecting the interior of the container with the eduction tube, a nozzle mounted on the eduction tube, and valve means associated with the liquid tube for controlling the flow of liquid therethrough withoutinterrupting the flow of air through the eduction tube.

2. A power spray gun comprising a hollow head, a container detachablyconnected therewith, means for introducing compressed air into the head, an eduction tube connected With the head and in communication with the interior thereof, a liquid tube carried by the head and connecting the interior of the container with the eduction tube, adjustable means for controlling the escape of `air,into the eduction tube after it contacts the liquid, a hand operated needle valve for controlling the fiow of liquid through the liquid tube, means for adjusting the valve, a nozzle having an elongated slit therein adjustably connected with the outer end of the eduction tube and means for centering the liquid tube in the eduction tube.

3. A power spray gun comprising a hollow head, a container detachably connected therewith, means for introducing compressed air into the head, an eduction tube connected with the head and in communication with the interior thereof, a liquid tube carried by the head and connecting-the interior of the container with the eduction tube, adjustable means for controlling the escape of air into the eduction tube after it contacts the liquid, a hand operated needle valve for controlling the flow of liquid through the liquid tube, means for adjusting the valve, a nozzle having an elongated slit therein adjustably connected with the outer end of the eduction tube, means for centering the liquid tube in the eduction tube, a partition placed between the head and container and having a valve controlled opening therein whereby air can pass from the head into the container but liquid is preventedv from passing from the container into the head.

4. A power spray gun comprising a hollow head, a container detachably connected therewith, an angle-shaped handle connected with the head, means for introducing compressed air into the head, some of this air entering the container and .placing the liquid therein under pressure, an eduction tube connected with the head and in communication therewith, adjus'table means for controlling the escape of air into the eduction tube after contacting liquid, a liquid tube carried by the head and connecting the interior of the' container with the eduction'tube, an adjustable nozzle on the outer end of the eduction tube having an elongated slit therein forming a fan-shaped spray, a needle valve passing through the head and when in closed position preventing the flow of liquid through the liquid tube, a spring pressed slidable member associated with the handle, means for adjustably connecting the needle valve to said member and a trigger pivoted to the handle and engaging a part of the slidable member whereby the valve will be unseated when the trigger member is moved toward the handle.

5. A power spray gun comprising a hollow head, a containerdetachably connected therewith, an angle-sh'aped handle connected with the head, means for introducing compressed air into the head, some of this air entering the container and placing the liquid therein under pressure, an eduction tube connected with the head andfin communication therewith, adjustable means for controlling the escape of air into the eduction tube after contaeting liquid, a liquid tube carried by the head and connecting the interior of the container with the eduction tube, an adjustable nozzle on the outer end of the eduction tube having an elongated slit therein forming a fan-shaped spray, l,a needle valve passing through the head and when in closed position preventing the flow of liquid through the liquid tube, a spring pressed slidable member associated with the handle, means forV adj ustably connecting the needle valve to said member, a trigger pivoted to the handle and engaging a part of the slidable member whereby the'valve Will be unseated When the trigger member is moved toward the handle, a valve carried by the head for closing communicat'ion between the head and the air supfily and a safety valve associated With the ead.

6. A spraying device comprising a container, a cap therefor, a hollow head mounted on the eap and having a space in communication With the container, aneduction tube mounted in the vhead and in communication With the interior of the head, a liquid tube mounted in the head and connecting the interior of the container with the eduction tube, a source of compressed air feeding into the hollow head, a Partition separating the air space of the hollow head from the container and having an opening therein, a valve controlling the opening whereby air can pass from ythe head into the container to force the liquid therein to the eduction tube and Whereby liquid is prevented from passing y from the container into the head, and means for causing the air passing through the eduction tube to act on the liquid emerging from the liquid tube, comprising a nozzle on the fore end of the eduction tube.

7 A spraying device comprising a container, a cap therefor, a holloW head mounted on the eap and having a space in communication with the container, an eduction tube mounted in the head and in communication with the interior of the head, a liquid tube mounted in the head and connecting the interior of the container with the eduction tube, a source of compressed air feeding into the hollovv head, a partition separating the air space of the hollow head from the container 'and having an openingtherein, a valve controlling thev opening whereby air can pass from the head into the container to force the liquid therein to the eduction tube and whereby liquid is prevented from passing from the container into the head, and means for causling the air passing through the eduction tube to act on the liquid emerging from the liquid tube, comprising a nozzle on the fore end of the eduction tube, said nozzle having an elongated slit th'erein to produce afan shaped w spray.

8. A compression power gun for producing a fan shaped spray, comprising a liquid container, a means for introducing compressed air into thecontainer, an eduction tube associated With the container and through which the compressed air passes, a slitted nozzle mounted on the eduction tube, having its interiorl Walls terminating in the slit and so converging as'to limit the flare of the fan shaped spray, a liquid tube connecting the interior of the eduction tube With the container, a valve for controlling the floW of the liquid through the liquid tube, Whereby the fiow of liquid is started and stopped, and means for adjusting the valve to regulate the quantity of liquid passing through the nozzle, Whereby the valve co-actswith the nozzle for prducing fan shaped sprays of Varying Wi ths.

In testimony Whereof I aflix my signature.

ISAAC W. P. BUCHANAN. 

